Columbia University Joint CS/EE Networking Seminar Series

Wireless Medium Access: From Local Interactions to Global Efficiency

Javad Ghaderi

University of Illinois at Urbana-Champaign

Apr. 19, 11:00AM, Interschool Lab, 750 CEPSR

Abstract:
Emerging wireless networks typically lack any centralized access control
entity, and instead vitally rely on the individual nodes to operate
autonomously and to efficiently share the medium in a distributed fashion.
This requires the nodes to schedule their individual transmissions and
decide on the use of a shared medium based on knowledge that is locally
available or only involves limited exchange of information. In this talk, I
will present a class of random access (CSMA-type) algorithms that use only
local queue-length information, yet could provide a striking capability to
match the throughput of centralized scheduling algorithms. I will
characterize the sharp conditions under which such throughput optimality
holds in general network topologies. The random access algorithm is
inherently distributed, and when combined with TCP-type congestion control
mechanisms, it can provide maximum throughput and Quality-of-Service in
multihop wireless networks with dynamic flows. The detailed analysis of the
local interactions in wireless networks can also serve as a useful tool in
the analysis of other complex networks.

Speaker Biography:
Javad Ghaderi is a Ph.D. candidate in the Department of Electrical and
Computer Engineering and the Coordinated Science Laboratory at the
University of Illinois at Urbana-Champaign (UIUC). He received his M.S. from
the University of Waterloo in 2008 and his B.S. from the University of
Tehran in 2006, both in Electrical and Computer Engineering. His research
interests include network algorithms, network control and optimization, and
network information theory. While at UIUC, he has spent summers working in
Qualcomm and Alcatel-Lucent Bell Laboratories. Javad is the recipient of the
Mac Van Valkenburg Graduate Research Award at UIUC, and is a finalist for
the Best Student Paper Award at the 2013 American Control Conference.